1. Field of the Invention
The present invention relates to a microscope including a line illumination.
2. Description of the Related Art
Known microscopes including line illumination include, for example, those disclosed in Japanese Unexamined Patent Applications Publication Nos. HEI-7-120681, HEI-10-104523, and 2003-167197.
In the microscope disclosed in Japanese Unexamined Patent Application Publication No. HEI-7-120681, which includes a conventional incident-illumination optical system with a single light source, a cylindrical lens is inserted between an aperture stop and an objective lens, and a circular beam of light formed by the aperture stop is focused to a straight line by the cylindrical lens to form a line illumination. Some of the light from the light source is thus wasted.
In the microscope disclosed in Japanese Unexamined Patent Application Publication No. HEI-10-104523, optical fibers are arranged side-by-side to form a line-shaped light source, and the light from this light source passes through a slit to form a line illumination.
In the microscope disclosed in Japanese Unexamined Patent Application Publication No. 2003-167197, a plurality of slits are arranged near a light source, and the light beams passing through these slits form a line illumination serving as illumination light. This arrangement has high light utilization efficiency.
However, in the microscope disclosed in Japanese Unexamined Patent Application Publication No. HEI-7-120681, since a circular beam is focused to a straight line by the cylindrical lens, the illumination is elliptical. Furthermore, this microscope suffers from the problem of luminance variation at the central region and the peripheral region of the ellipse.
The microscope disclosed in Japanese Unexamined Patent Application Publication No. HEI-10-104523 suffers from the problem in that the optical fibers serving as the light source have low light utilization efficiency.
In the microscope disclosed in Japanese Unexamined Patent Application Publication No. 2003-167197, since only the light passing through the slits forms the line illumination, there is still a large amount of light that cannot pass through the slits, and therefore, the light utilization efficiency is not high enough.